/*
 * jQuery JSON Plugin
 * version: 1.0 (2008-04-17)
 *
 * This document is licensed as free software under the terms of the
 * MIT License: http://www.opensource.org/licenses/mit-license.php
 *
 * Brantley Harris technically wrote this plugin, but it is based somewhat
 * on the JSON.org website's http://www.json.org/json2.js, which proclaims:
 * "NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.", a sentiment that
 * I uphold.  I really just cleaned it up.
 *
 * It is also based heavily on MochiKit's serializeJSON, which is 
 * copywrited 2005 by Bob Ippolito.
 */

(function ($) {
    function toIntegersAtLease(n)
    // Format integers to have at least two digits.
    {
        return n < 10 ? '0' + n : n;
    }

    Date.prototype.toJSON = function (date)
        // Yes, it polutes the Date namespace, but we'll allow it here, as
        // it's damned usefull.
    {
        return this.getUTCFullYear() + '-' +
            toIntegersAtLease(this.getUTCMonth()) + '-' +
            toIntegersAtLease(this.getUTCDate());
    };

    var escapeable = /["\\\x00-\x1f\x7f-\x9f]/g;
    var meta = {    // table of character substitutions
        '\b': '\\b',
        '\t': '\\t',
        '\n': '\\n',
        '\f': '\\f',
        '\r': '\\r',
        '"': '\\"',
        '\\': '\\\\'
    };

    $.quoteString = function (string)
        // Places quotes around a string, inteligently.
        // If the string contains no control characters, no quote characters, and no
        // backslash characters, then we can safely slap some quotes around it.
        // Otherwise we must also replace the offending characters with safe escape
        // sequences.
    {
        if (escapeable.test(string)) {
            return '"' + string.replace(escapeable, function (a) {
                    var c = meta[a];
                    if (typeof c === 'string') {
                        return c;
                    }
                    c = a.charCodeAt();
                    return '\\u00' + Math.floor(c / 16).toString(16) + (c % 16).toString(16);
                }) + '"';
        }
        return '"' + string + '"';
    };

    $.toJSON = function (o) {
        var type = typeof(o);

        if (type == "undefined")
            return "undefined";
        else if (type == "number" || type == "boolean")
            return o + "";
        else if (o === null)
            return "null";

        // Is it a string?
        if (type == "string") {
            return $.quoteString(o);
        }

        // Does it have a .toJSON function?
        if (type == "object" && typeof o.toJSON == "function")
            return o.toJSON();

        // Is it an array?
        if (type != "function" && typeof(o.length) == "number") {
            var ret = [];
            for (var i = 0; i < o.length; i++) {
                ret.push($.toJSON(o[i]));
            }
            return "[" + ret.join(",") + "]";
        }

        // If it's a function, we have to warn somebody!
        if (type == "function") {
            throw new TypeError("Unable to convert object of type 'function' to json.");
        }

        // It's probably an object, then.
        var ret = [];
        for (var k in o) {
            var name;
            type = typeof(k);

            if (type == "number")
                name = '"' + k + '"';
            else if (type == "string")
                name = $.quoteString(k);
            else
                continue;  //skip non-string or number keys

            var val = $.toJSON(o[k]);
            if (typeof(val) != "string") {
                // skip non-serializable values
                continue;
            }

            ret.push(name + ":" + val);
        }
        return "{" + ret.join(",") + "}";
    };

    $.compactJSON = function (o) {
        return $.toJSON(o, true);
    };

    $.evalJSON = function (src)
        // Evals JSON that we know to be safe.
    {
        return eval("(" + src + ")");
    };

    $.secureEvalJSON = function (src)
        // Evals JSON in a way that is *more* secure.
    {
        var filtered = src;
        filtered = filtered.replace(/\\["\\\/bfnrtu]/g, '@');
        filtered = filtered.replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']');
        filtered = filtered.replace(/(?:^|:|,)(?:\s*\[)+/g, '');

        if (/^[\],:{}\s]*$/.test(filtered))
            return eval("(" + src + ")");
        else
            throw new SyntaxError("Error parsing JSON, source is not valid.");
    };
})(jQuery);
